<!DOCTYPE html>
<html lang="en">
  <head>
    <meta charset="UTF-8" />
    <meta http-equiv="X-UA-Compatible" content="IE=edge" />
    <meta name="viewport" content="width=device-width, initial-scale=1.0" />
    <title>Document</title>
  </head>
  <body>
    <div id="test"></div>
    <script>
      /* 冒泡排序 */
      /*  var arr = [49, 38, 65, 97, 76, 13, 27, 49]
      for (var i = 0; i < arr.length; i++) {
        for (var j = 0; j < arr.length - i - 1; j++) {
          if (arr[j] > arr[j + 1]) {
            var temp = arr[j]
            arr[j] = arr[j + 1]
            arr[j + 1] = temp
          }
        }
      } */
      /* 数组去重 new Set() */
      // var arr = ['q', 'a', 'b', 'a', 'b', 'a']
      // let newArr = new Set(arr)
      // console.log(newArr)
      // console.log(arr)
      /*  */
      /*  var str = '-webkit-background-image'

      var arr = str.split('-')
      arr.forEach((item) => {
        item.charAt(0) = item.charAt(0).toUpperCase()
        // item.charAt(0).replace(item.charAt(0).toUpperCase())

        console.log(item)
      })
      console.log(arr) */
      // console.log(newarr)
      const value = document.getElementById('test')
      console.log(typeof value)
    </script>
  </body>
</html>
